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991.
992.
Giuseppe G. G. Manzardo Sandra Kürsteiner-Laube und Daniel Perrin 《Zeitschrift für Lebensmitteluntersuchung und -Forschung A》1996,203(6):501-506
In diethyl ether extracts from celeriac (Apium graveolens L. var.rapaceum) all four stereoisomers of (3a–7a)-cis-3-butylhexahydrophthalide were found to be present. The analyses were carried out by means of GC, enantioselective GC and GC-MS. The assignment of the relative configuration of the diastereomers3 and4 was accomplished by NOE difference spectroscopy. 相似文献
993.
The pyrolysis of tertiarybutylphosphine (TBP) has been studied in the low pressure conditions used for chemical beam epitaxy
(CBE). The pyrolysis studies were carried out in low pressure reactors of two different configurations, one of which is a
cracker cell designed for use in a CBE system. The reaction products were studied using a quadrupole mass spectrometer. The
products observed are accounted for by a reaction mechanism involving homolysis of the parent TBP molecule to produce PH2 and C4H9 radicals. These undergo subsequent reactions to form the stable products C4H8, PH3 and H2, with smaller amounts of P and P2 being produced. The production of the sub-hydride PH2 using this cracker cell design indicates that the use of partially cracked TBP may be a promising technique for reducing
the amount of carbon incorporated into the growing epitaxial layer. 相似文献
994.
OntheRealizationofCurrent-ModeContinuousTimeOperationalTransconductanceCapacitanceFilter¥GuoJingboandHanQingquan(ChangchunPos... 相似文献
995.
开关电流技术:一种新的模拟抽样数据处理方法 总被引:1,自引:0,他引:1
开关电流(SI)技术是一种新的模拟抽样数据处理技术,介绍了开关电流电路的基本单元结构,讨论了目前开关电流技术中存在的问题及其解决方法。对开关电流技术与开关电容技术的一些基本特征进行了比较,SI技术不仅结构简单,而且与标准CMOS工艺兼容,可望替代开关电容电路。 相似文献
996.
TORGILS FOSSEN ØYVIND M. ANDERSEN DAG OLAV ØVSTEDAL ATLE T. PEDERSEN ÅSE RAKNES 《Journal of food science》1996,61(4):703-706
Three red onion (Allium cepa) cultivars, top onion (A. cepa var. vivi-parum), A. altaicum and chive (A. schoenoprasum) contained several or all of the following anthocyanins: 3-(6′-malonyl-3′-glucosylglucoside), 3-(3′,6′-dimalonylglucoside), 3-(6′-malonylglucoside), 3-(3′-malonyl-glucoside), 3-(3′-glucosylglucoside) and 3-glucoside of cyanidin. Trace amounts of two pelargonidin derivatives and the 3,5-diglucosides of cyanidin and peonidin were for the first time reported in red onion. Carbon NMR data showed that the sugars of the 3-(6′-malonyl-3′-glu-cosylglucoside), 3-(6′-malonylglucoside) and 3-glucoside of cyanidin were pyranoses. Substitution either by sugar or acid in the sugar 3-position of an anthocyanin has never been reported outside the genus Allium. 相似文献
997.
Claes-Gran Johansson 《Journal of the Institute of Brewing》1996,102(4):249-250
A combustion method, relying on the Dumas principle, for the determination of total nitrogen in barley and malt, has been collaboratively tested by the Analysis Committee of the European Brewery Convention. Repeatability, r95, and reproducibility, R95, values were 0.063 and 0.116% of dry matter, respectively, for samples with nitrogen contents in the range 1.23 to 1.86% N of dry matter. There was no significant difference between these values for barley and malt. The Analysis Committee approved the adoption of the combustion method for inclusion in Analytica EBC as an alternative method. 相似文献
998.
本文介绍了汉英机器翻译系统中从中间媒介语言生成英语的生成系统的词汇结构和功能,描述了生成系统各个层次之间的转换原理。为了说明清楚,在叙述中注意了列举从中间媒介中间媒介语言到目标语句的生成实例。 相似文献
999.
续竞存 《固体电子学研究与进展》1996,16(3):254-258
用电荷控制及热电子弹道运动模型计算InAs/InP0.7Sb0.3热电子晶体管的截止频率fT及最高振荡频率fmax。结果表明,fT、fmax分别达到280GHz及600GHz。并指出,通过生长GaSb中间层,InAs/InP0.7Sb0.3HET可在GaAs衬底上实现单片集成。 相似文献
1000.
It is possible to optimize the performance of the inorganic-organic composites dispersing the inorganic component in the organic matrix on a nanomiter length scale. If dry the inorganic phase cannot be intimately dispersed during the incorporation in the matrix. When the particle surface is organically modified, and the incorporation is made starting from a liquid dispersion (particles in polymer solution), the resulting composites exhibit an excellent homogeneity. Here, monolithic [poly(methyl methacrylate)/monodisperse silica particles] nanocomposites have been prepared and characterized by scanning electron microscopy (SEM), transmission electron microscopy (TEM), dynamic light scattering (DLS), micro-hardness, and differential scanning calorimetry (DSC). 相似文献